how about this for a switch design?

Knowing little about the inards of electronics and even less about LED technology, I have a thought about a switch design. Perhaps someone with a bit more understanding could chime in and tell me if this is a good idea or can't really be done.

Why not have a tailcap switch with a rotating ring around it. Hit the switch to turn on the light to full power, then dial down the output to the level you like. Sort of like a fader. Sounds like the U2 does this, but the ring is closer to the head. I'm thinking of the ring right at the same thumb for the on switch and I'm thinking infinite light levels.

Possible? Good idea?

Stupid? Can't be done?

That'd be a great tailcap design. Put a little resistance or silent detents in the ring and it'd be perfect.

Agreed. It would need to have a fairly heavy "quality" feel to it. Resistence or detents would do that well.

The idea came to me from my Accord's radio knob. Same concept, with power in the middle and volume knob around the power button. Of course, it is too big for a light, but the idea seemed solid.

The clicky would have to be recessed, I think. Running my thumb around the button on my Surefire G2, it gets caught on the button. Maybe the selector ring could have some light knurling for grip.